As is known in the wireless telecommunication arts, an IP Multimedia Subsystem (IMS) is an architectural framework (originally designed by the wireless standards body 3rd Generation Partnership Project (3GPP)) for delivering IP multimedia to wireless mobile device users. That is to say, the IMS supports the use of IP multimedia applications and/or services within a wireless telecommunications system or network. Generally, IMS enables wireless network service providers and/or operators to offer their subscribers (i.e., mobile users) multimedia services based on and/or built upon Internet applications, services and/or protocols (e.g., including SIP (Session Initiation Protocol), which is used to manage the IP multimedia sessions).
Generally, in the field of wireless telecommunications and/or packet-switched networks, the term Quality of Service (QoS) relates to resource reservation control mechanisms. For example, these mechanisms provide different QoS levels and/or classifications to different users and/or data flows, or supply a certain level of performance to network traffic in accordance with established rules and/or policies. For example, some traffic types (such as real-time or interactive traffic) generally demand a higher QoS level to achieve adequate performance, while a lower QoS level may suffice for other types of traffic. At any given time there may be a limited amount of network resources available for the particular traffic load being experienced at that time. Accordingly, it is typically desirable to provide varied QoS levels to different data flows based upon the type of traffic each data flow represents so as to optimize resource allocation and/or management (e.g., including bandwidth dedication, jitter and/or latency control, loss characteristic management, etc.).
Commonly, the rules and/or policies for permitting access to various multimedia applications and/or services via the IMS and/or for setting or otherwise determining QoS levels are established with the aid of a Policy Control Rule Function (PCRF). The policy function generally coordinates the various network resources to provide requested services to authorized subscribers at the appropriate QoS levels. It is responsible for identifying the policy rules for the services that subscribers may intend using. The policy control architecture determines and enforces dynamic QoS and regulates access permission policies for the network infrastructure elements involved in providing a specific requested service. The PCRF is the node designated in real-time for the determination of the policy rules. For example, a set of policy rules can be activated to verify access permission, manage QoS etc., all in real-time. The PCRF enforces these policy rules through its interaction with a Policy Control Enforcement Function (PCEF) implemented at the access gateway node. The policy rules can be formulated based on static information (e.g., such as a subscription profile maintained in a Subscriber Policy Repository (SPR)), dynamic information, and the available resources. Accordingly, the combination of such rules, once met for a service request, can trigger a desired action; such as—allowing the service with the requested bandwidth or appropriate QoS level, or denying the service. This type of framework for the policy rules allows wireless network operators to deploy service logic while optimally utilizing the network resources.
With reference now to FIG. 1, there is shown relevant portions of a visited and a home telecommunications network. In a typical wireless or mobile roaming scenario, a multimedia enabled mobile node (MN), mobile terminal (MT) or mobile station (MS)—generally referred to herein as user equipment (UE) 10—may support two IP tunnels 20 and 22 to access selected IP multimedia applications and/or services, e.g., via the appropriate IMS. The use of two IP tunnels in this manner is commonly referred to as dual IP anchoring. As can be appreciated, each tunnel generally may carry various different types of traffic or data flows to and/or from the UE 10.
As illustrated, the first IP tunnel 20 is commonly anchored at the local or visited network, i.e., at a local access gateway 30. Generally, the tunnel 20 typically carries bearer traffic to and/or from the UE 10. By anchoring the tunnel 20 locally, bearer traffic routing can be optimized, e.g., by not having to backhaul this traffic to the home network. Accordingly, a reduction in transport and/or equipment costs and/or overhead can be realized. The second IP tunnel 22 is commonly anchored at the home network, i.e., at a home gateway 40. Generally, the tunnel 22 typically carries control signalling and/or application data to and/or from the UE 10. In this manner, the home network is more readily able to retain a significant degree of control over the IP multimedia applications and/or services accessed via the IMS by the UE 10.
However, in conventional embodiments, packet filtering and policy enforcement is only applied in and/or supported at the local access gateway 30 for traffic carried by the tunnel 20. As illustrated, this is achieved by a packet classification function and/or PCEF 32 implemented at the local access gateway 30. That is to say, generally, packet filtering is only applied in the local access gateway 30 to classify downlink traffic (i.e., traffic carried by the tunnel 20 to the UE 10) into a plurality of individual service or data flows (e.g., data flows 20a, 20b, . . . 20n) each with an appropriate QoS level suited to the particular traffic type—e.g., best effort, real-time audio and video, etc. Similarly, policy enforcement is also only supported at the local access gateway 30, e.g., in accordance with policy rules propagated to the PCEF 32 from a SPR 50, a home PCRF (hPCRF) 52 and/or a visited PCRF (vPCRF) 54.
As can be appreciated from the illustrated architecture, packet classification and/or policy enforcement is traditionally not supported in the home gateway 40 for the tunnel 22. Rather, all types of “home traffic” are transported within the one tunnel 22. Consequently, the lack of QoS differentiation in the tunnel 22 can result in congestion and/or delays for otherwise high priority traffic and undesirably downgrade total resource efficiency.
Accordingly, a new and improved system and/or method is provided that overcomes the above-referenced problems and others.